USA Today reports that "as solar costs plummet, U.S. corporate giants including Apple, Google and Wal-Mart are turning to the sun to power stores, data centers and other facilities."

"At a Wal-Mart store in Mountain View, Calif., on Friday, President Obama cited Wal-Mart's commitment to double the number of solar energy projects at its stores, Sam's Clubs and distribution centers nationwide by 2020. Obama announced 300-plus other private and public efforts, including new solar panels on the White House, to boost energy efficiency and renewable power."

"Apple, for example, pledged to power all its facilities with green energy. The California-based company said its energy-intensive data centers already use 100% renewable power and so will the 2.8 million square-foot headquarters it's building in Cupertino, which will feature a mammoth rooftop solar array."